Diesel engines include cylinders that combust a mixture of compressed air and diesel fuel. Frequently, exhaust gas recirculation (EGR) is utilized to minimize generally undesirable emissions, such as NOx emissions, during the combustion of the diesel fuel. The utilization of exhaust gas recirculation during combustion often impacts fuel economy, especially in turbocharged diesel engines.
In traditional EGR systems, the poor mixing of EGR gas with fresh air may result in an uneven distribution of the recirculated exhaust gas provided to the cylinders of the engine. Accordingly, some of the engine cylinders may become overloaded with EGR gases while other cylinders may receive very little EGR gas. Moreover, when the EGR flow rates are increased, the poor EGR mixing may result in a large increase in engine-out smoke emissions. In an attempt to even the distribution of the EGR gas throughout the cylinders, traditional mixer designs often result in a fresh air intake restriction.